fix: switch solver replays to single-column layout for reliable visibility

Changed the solver results grid from 2-column to single-column flex layout.
Ensures all solver MiniBoards (including Vowel First with its 6-step rows)
are always fully visible regardless of varying step counts between solvers.

client/src/screens/Screen3Results.tsx

@@ -133,7 +133,7 @@ export function Screen3Results({ won, attemptCount, revealedWord, stats, replays
           <p style={{ fontSize: '0.85rem', color: '#787c7e', marginBottom: '12px' }}>
             {r.solverCaption}
           </p>
-          <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: '16px', maxWidth: '320px', margin: '0 auto' }}>
+          <div style={{ display: 'flex', flexDirection: 'column', gap: '16px', maxWidth: '280px', margin: '0 auto' }}>
             {replays.map((rp) => (
               <MiniBoard key={rp.solver} replay={rp} targetWord={revealedWord} />
             ))}